| n | a(n) |
|---|---|
| 1 | 81 |
| 2 | 288 |
| 3 | 1024 |
| 4 | 3840 |
| 5 | 14400 |
| 6 | 53760 |
| 7 | 200704 |
| 8 | 752640 |
| 9 | 2822400 |
| 10 | 10536960 |
| 11 | 39337984 |
| 12 | 147517440 |
| 13 | 553190400 |
| 14 | 2065244160 |
| 15 | 7710244864 |
| 16 | 28913418240 |
| 17 | 108425318400 |
| 18 | 404787855360 |
| 19 | 1511207993344 |
| 20 | 5667029975040 |
| 21 | 21251362406400 |
| 22 | 79338419650560 |
[81,288,1024,3840,14400,53760,200704,752640, 2822400,10536960,39337984,147517440,553190400, 2065244160,7710244864,28913418240,108425318400, 404787855360,1511207993344,5667029975040, 21251362406400,79338419650560] |